1. Field of Invention
This invention relates to a liquid crystal device and the manufacturing method thereof. Moreover, this invention particularly relates to a liquid crystal device and manufacturing method for simultaneously forming conductive and/or insulating walls using Thin Film Transistor (TFT) Deposition as well as pixel electrode therein.
2. Description of Prior Art
The present liquid crystal device process comprises forming of Thin Film Transistor (TFT), Liquid Crystal Device (LCD) panel, and liquid crystal module. Common TFT structure includes gate metal layer, semiconductor layer (wherein semiconductor layer includes gate insulating layer, amorphous crystalline layer, and a n+ doping layer), source/drain metal layer, and passivation layer. The forming of TFT process includes repeated rinsing, deposition, yellow light exposure, developing, etching, and lift-off. Take gate metal layer for example, a substrate is rinsed firstly, followed by depositing a metal layer on substrate surface, coating photoresist on the metal layer, exposed under light, developing away the unwanted pattern, etching for desired pattern, and finally lift off the photoresist to form a gate metal layer. Continue on next mask accordingly.
The process of forming a LCD panel mainly comprises One Drop Fill process, i.e. ODF process, as shown in FIG. 1A. A sealant, an Ultraviolet sealant (UV sealant) for example, is applied to a substrate A1 in an enclosed form, and liquid crystal is dropped from a liquid crystal dispenser to the enclosed area as shown in FIG. 1B. After forming a uniform liquid crystal layer A4, take another substrate A2 to bond to substrate A1 that has the liquid crystal layer A4, and continue to irradiate (ultraviolet light, for example) the sealant A3 so as to adhere the two substrates A1 and A2 together (as shown in FIG. 1C). After an annealing process, the procedure is ultimately done.
However, the drawback to this technique is, some part of the liquid crystal layer A4 would be exposed to lighting when irradiating sealant A3 in order to adhere substrates A1 to A2, thus liquid crystal suffers from degradation.
Moreover, the liquid crystal layer A4 that contacts with the sealant A3 is possibly contaminated, which also down-grades display quality.
In order to avoid contact contamination between the liquid crystal A4 and the sealant A3, the US patent U.S. Pat. No. 6,219,126 discloses a method using coating or lithography techniques for building an enclosed liquid crystal wall structure that is made of acrylic resin or silicone. Nevertheless, the structure requires excess materials and steps that complicate the process.
JP patent JP2001-222017 as well discloses that in order to implement liquid crystal wall equivalency, a pigment-layer of deposited CF (color filter) substrate is used (as shown in FIG. 3). Yet in order to avoid liquid crystal degradation caused by ultraviolet lighting, masking effect has to be tied with pigment color as well as concentration control thereof.
Another prior art as shown in FIG. 4, a liquid crystal device comprises a TFT substrate B1 and a Color Filter (CF) substrate B2 in parallel with a liquid crystal layer B3 therebetween. When TFT substrate B1 that is voltage driven has a potential difference from CF substrate B2, the transmittance of the liquid crystal molecules is manipulated by voltage difference thereof. Generally, the voltage applied to CF substrate B2 is fixed as a common voltage Vcom so as to vary voltage V applying to pixel electrode B11 on TFT (not shown) to generate a potential difference ΔV=V−Vcom. However, there is no terminal to CF substrate B2, Vcom voltage has to be provided by TFT.
For instance, usually Vcom voltage on TFT substrate B1 is transmitted to CF substrate B2 through conductive adhesive B4, however, it has to be done outside of sealant B5 by applying excess conductive adhesive B4 with an excess device. Obviously there is excess material cost and as well as the process has to be done after sealant is hardened.
In addition, as disclosed in US patent U.S. Pat. No. 6,404,480, a conductive spacer B6 is used to support and conduct TFT substrate B1 and CF substrate B2 as well as to be mixed with sealant B5 (as shown in FIG. 5), so as to perform conducting Vcom voltage. Yet conductive material is required and the process difficulty is raised and all sealant B5 is possibly not hardened.